Is it okay to do 2 sessions of DMSI on 1 day?

[Superman]

Technically you're not breaking ASRB. You're taking the right amount of break time in between your loops. ASRB only applies to consecutive loops and listening. If you did half a loop and then started another one immediately after then you would be breaking ASRB. As long as your doing complete loops you won't be breaking ASRB even if the sessions are hours apart. As long as you listen to the track from beginning to end.